The present invention relates to an improved key mechanism for a wood wind, and more particularly relates to an improvement in construction of a key mechanism of a wood wind such as a bass clarinet for generation of a crisp B-flat sound.
A wood wind is in general provided with a key mechanism which extends over its upper and lower joints. Such a key mechanism includes a register key unit, a G/D key unit and an A key unit. The register key unit is provided with a register key mechanically coupled to a cap for controlling the state of a lower vent tube. The G/D key unit is provided with a G/D key. The A key unit is provided with an A key mechanically coupled to a cap for controlling the state of an A sound hole.
For generation of a B-flat sound, the left index finger of the player operates the A key of the A key unit and the associated cap releases the A sound hole. Concurrently, the player's left thumb operates the register key and the associated cap releases the lower vent tube. Thus, once the wood wind is blown via its mouthpiece, two air columns vibrate in the wood wind for generation of the B-flat sound. The period of the basic vibration of the first air column is fixed by the distance between the mouthpiece and the lower vent tube whereas the period of the basic vibration of the second air column is fixed by the distance between the mouthpiece and the A sound hole. In general on a wood wind, the lower vent tube is quite distant from the A sound hole along the length of the wood wind. As a consequence, the first and second air columns are quite different in period of basic vibration from each other. Such a significant difference in period of basic vibration results in generation of a B-flat sound which includes growls and lacks in crispness.
In order to obviate such a problem, one alternative is to provide a new sound hole adapted for independent generation of a B-flat sound. This expedient, however, requires change in the traditional finger motion by the player for operation on an associated new key and, as a consequence, quite unemployable in practice.